There are currently no blood or laboratory tests that have been proven to help in diagnosing sporadic Parkinsons disease. The diagnosis is based on a thorough medical history and neurologic examination. Patients exposed to toxins, such as manganese, MPTP (1-methyl-4-phenyl-1,2,3,6-
tetrahydropyridine), or carbon monoxide; patients with a history of repetitive head trauma or infections, such as HIV or Creutzfeldt-Jakob disease; or patients taking neuroleptic or antiemetic medications may display signs and symptoms of Parkinsonss disease.